Alphabet Suffers Its Worst Day Ever as Wall Street Doubts AI Payoff

On Thursday 29 October 2026, Alphabet's shares fell more than 12 percent — the company's worst single-session decline since going public in 2004 — erasing approximately $500 billion in market capitalisation, the second-largest single-day market-value wipeout in stock-market history after Nvidia's $600 billion drop in early 2025. The sell-off was triggered by third-quarter results that missed Wall Street expectations on several fronts: revenue came in at $127.58 billion against a forecast of $128.2 billion, adjusted earnings per share of $2.67 fell well short of the $3.02 analysts expected, and search-advertising revenue of $63.35 billion grew only 12 percent — slower than hoped. Capital expenditure more than doubled to $51.4 billion for the quarter as Alphabet poured money into AI data centres and infrastructure, pushing free cash flow to negative $9.1 billion for a second consecutive quarter. Google Cloud revenue nearly doubled to $30.7 billion, beating projections, but could not offset investor concerns. The results renewed debate about whether the enormous bets being placed across the industry on artificial intelligence will generate adequate returns quickly enough. The broader tech index also fell on the news, although rival Microsoft's shares ended flat.